Cables made of metal wire for the reinforcement of plastic and elastic articles are known. These cables essentially consist of strands made from single wires. The strands, with or without a core, are twisted together to form a cable. However, there are also cables known, the strands of which, before they are twisted together, are twisted around or wrapped in textile fibers. The cables, the strands of which are twisted around with textile fibers, have a relatively high flexibility, but have, relative to the diameter of the cable, a relatively low tensile strength. Cables made of strands that are not wrapped in textile fibers, on the other hand, have a relatively high tensile strength and a relatively low flexibility.
The known cables made of metal wire are used to reinforce plastic and elastic articles and especially conveyor belts. The mechanical properties e.g. of the conveyor belts are essentially determined by the cables that have been inserted to reinforce it, whereby these stretch in the longitudinal direction of the conveyor belt, with spaces between them.
Conveyor belts with cables that have strands without textile fibers have, relative to the diameter of the cable, a relatively high tensile strength but, unfortunately, a relatively low flexibility.
Conveyor belts that have cables with strands that are wrapped around with textile fibers, on the contrary, have a relatively high flexibility and a low tensile strength, calculated on the diameter of the cable. These conveyor belts have a relatively low metallic cross section.
Furthermore, a cable made of metal wire is known, in which the strands are placed around a single plastic core, whereby the plastic core has flanges that protrude outward. These flanges protrude clearly beyond the circumference of the strands in order to reach certain friction values between the guide rollers and the cable. For the production of these cables a relatively high foregoing effort is required, as well as greater consumption of material. Moreover, this cable exhibits a relatively low flexibility and a relatively large outside diameter.
Cables of metal wire with non-wrapped strands are made on known cable-making machines, whereby the strands are pulled off from reels, are gathered together in the twisting head of the cable-making machine and are there twisted into a cable. Cables with wrapped strands are made in the same way, whereby strands are pulled off the reels, which strands are already wrapped in textile fibers.